JPS5849055A - Salient-pole type rotor - Google Patents

Abstract

PURPOSE:To obtain a salient-pole type rotor which is rigid in its mechanical strength and which has small vibrating torque at the starting time by simultaneously clamping annular low resistance conductors between a pole head and the support for a rotor shaft. CONSTITUTION:An annular low resistance conductor 8 made of copper or the like is interposed between the back surfaces of both ends of a pole head 1 and an annular support 6 for supporting the centrifugal force of a field coil 4 projected from a rotor shaft 5, and is clamped by a clamping bolt 3. The conductors 8 can be continuously attached to the outer peripheral surface of the support 6. With this structure, the vibrating torque at the starting time can be reduced, and its electrolytic corrosion caused due to the arc produced owing to the incomplete contact can be prevented, thereby enabling to manufacture a high speed rotor.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotating electrical machine, and in particular relates to a salient pole rotor with a lumpy magnetic pole structure.A salient pole rotor with a lumpy magnetic pole structure is widely used as a self-starting synchronous motor. In particular, during acceleration, the heat capacity of the magnetic pole head against the secondary loss generated by the rotor is large, so it is suitable for synchronous motors that require heavy load starting.

For these reasons, synchronous motors have become larger in capacity and faster, and high-speed rotors with large rotor diameters, such as those with rotor peripheral speeds exceeding 100 rq/sec, have been designed. . Conventionally, such a high-speed rotor is manufactured using a rotor, for example, as shown in FIG. The rotor shaft 54 has a two-shrink fit or one-piece forged structure with an upright structure.On the other hand, when a salient pole type block magnetic pole synchronous motor is self-started as an induction motor, the torque generated by the motor is: It is well known that the saliency of the rotor and the effect of the field winding C; due to impedance imbalance between the straight and horizontal axes, the torque in one direction, which is effective for acceleration, is doubled. .

Since this vibration torque varies widely from twice the source frequency to zero during acceleration, there is usually a point during startup that coincides with the torsional natural frequency of the shaft system of the motor and load. For this reason, the vibration torque generated by the electric motor (2) may cause extreme stress on the shaft due to resonance due to torsional vibration of the drive shaft system (2), or the gear of the speed increaser between it and the load machine may be struck and damaged. An important point for a self-starting synchronous motor is to reduce the vibration torque generated during starting.

As a conventional measure to reduce this, for example, as shown in Figure 2, a short-circuit ring 7 made of di-copper or other low-resistance material is provided to short-circuit the poles. It is possible to try to reduce the torque, but
As mentioned above, in the case of a high-speed rotor where the rotor circumferential speed exceeds 100 rrlec, as long as the above-mentioned structure is adopted, the strength of the short-circuiting ring 7 may be insufficient and a gap between the short-circuit ring 7 and the end face of the magnetic pole head may occur due to this during rotation. In some cases, it was impossible to manufacture due to electrolytic corrosion.

Short-circuiting due to the trench - In order to maintain the drive shaft system even with large vibration torque without providing a ring, an extremely expensive flexible coupling is used to directly connect the motor and load to reduce the resonance of screw vibration in the drive shaft system. In other cases, it was not possible to provide a self-starting synchronous motor.

An object of the present invention is to eliminate the above-mentioned drawbacks and provide a salient pole rotor that is mechanically strong and capable of reliably reducing the vibration torque generated during startup even in a high-speed rotor with a large rotor diameter. shall be.

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4.

In this embodiment I, between the back surface of both ends of the magnetic pole head 1 and the annular support 6 raised from the center of the rotor shaft 5: an annular low-resistance conductor made of other materials such as copper. 8 are sandwiched and fastened with tightening bolts 3, so that the low resistance conductor 8 is continuously attached to the outer peripheral surface of the support 6.

It is clear that with such a structure, the low-resistance conductor 8 can act as a short-circuit ring around the end of each magnetic pole, increase the horizontal axis current, and reduce the pulsating torque at the time of starting. .

In addition, the low-resistance conductor 8 is firmly fixed between the magnetic pole head 3 and the support 6, so even if a large current flows, it is possible to prevent arcs from popping out due to incomplete contact and cause electrolytic corrosion, and the stress caused by rotation is low. As mentioned above, a high-speed rotor can be manufactured.

In addition, since the I-support 6 is also located around the end of each magnetic pole, a magnetic path for leakage magnetic flux is formed between the magnetic poles, and the field is twisted between the two and six sides, which increases the leakage reactance of the field winding 4. It is clear that by reducing the influence of the magnetic winding, the unbalance of impedance between the vertical axis and the horizontal axis (as mentioned above) can be reduced, and the vibration torque at startup can be reduced.〇As explained above, According to the present invention (2), it has a simple structure of just tightening an annular low-resistance conductor between the magnetic pole head and the support of the rotor shaft, has a strong mechanical strength, and has a strong mechanical strength during startup. A salient pole rotor with low vibration torque can be provided.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view showing the conventional magnetic pole structure, and Figure 2 is a vertical cross-sectional view showing the conventional magnetic pole structure.
Fig. 3 is an enlarged view of the human part, and Fig. 3 is a longitudinal cross-sectional view showing an embodiment of the structure of the magnetic pole head end of a salient pole rotor according to the present invention.
Fig. 4 is a view in the direction of the @B” arrow in Fig. 3. 1... Magnetic pole head 2... Magnetic pole body 31., Tightening bolt 4... Field winding 5... Rotation shaft
6... Support body 7... Short circuit ring 8... Low resistance conductor. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] A salient pole type rotor with a rotor shaft 2, a field winding wound thereon, and a plurality of nine block magnetic poles, an annular support protruding from the rotor shaft, and a magnetic pole head. A salient pole rotor characterized by having an annular low resistance conductor fixed between the back surface of both shaft ends of the rotor.